I don't know why Sage return 0 for integrate(sin(2*x).abs(),(x,0,pi)) when its value is 2

When I try integrate(sin(x).abs(),(x,0,pi)) the program return the same thing. The numerical integration is correct, the program return (1.9999999999999998, 2.220446049250313e-14). I don't know if it is a bug or what. Any help? I have tried sage 6.2, 6.3, 6.4.1

Not that this is all that useful, because if we call this f then f(pi) has division by zero error, and based on comments elsewhere it is probably wrong in any case. I have to admit I am surprised this isn't doable, though. See this ticket 17511 but there are lots of places this question has recurred.